Valacyclovir use while Breastfeeding
Drugs containing Valacyclovir: Valtrex
Valacyclovir Levels and Effects while Breastfeeding
Summary of Use during Lactation
The dosage of acyclovir in milk after valacyclovir is less than 1% of a typical infant dosage and would not be expected to cause any adverse effects in breastfed infants. No special precautions are required.
Drug Levels
Valacyclovir is a prodrug that is rapidly converted to acyclovir in the body.
Maternal Levels. Five mothers who were nursing neonates were given valacyclovir 500 mg orally every 12 hours for 5 days. Valacyclovir was not detected in milk. Median peak acyclovir concentrations in milk of 4.2 mg/L occurred at 2 to 4 hours after the first dose and was similar after the last dose. The authors calculated the median milk concentration at steady-state to be 2.24 mg/L. The median half-life in milk was 2.1 hours (range 1.3 to 12.2 hours).[1] Using the median milk levels from this study, an exclusively breastfed infant would receive 0.34 mg/kg daily by mouth with this regimen, which is less than 1% of dosage given to neonates.
Infant Levels. The urine of 5 infants whose mothers were taking valacyclovir 500 mg every 12 hours orally was collected. Valacyclovir was not detected in any of the infant's urine. The median infant urine acyclovir concentration on day 5 of therapy was 0.74 mg/L.[1]
Effects in Breastfed Infants
Relevant published information was not found as of the revision date.
Possible Effects on Lactation
Relevant published information was not found as of the revision date.
Alternate Drugs to Consider
References
1. Sheffield JS, Fish DN, Hollier LM et al. Acyclovir concentrations in human breast milk after valaciclovir administration. Am J Obstet Gynecol. 2002;186:100-2. PMID: 11810093
Valacyclovir Identification
Substance Name
CAS Registry Number
124832-27-5
Drug Class
- Antiinfective Agents
- Antiviral Agents
Administrative Information
LactMed Record Number
393
Information from the National Library of Medicine's LactMed Database.
Last Revision Date
2009-02-03
Disclaimer
Information presented in this database is not meant as a substitute for professional judgment. You should consult your healthcare provider for breastfeeding advice related to your particular situation. The U.S. government does not warrant or assume any liability or responsibility for the accuracy or completeness of the information on this Site.
See Also...
- Valacyclovir use during Pregnancy
- Valacyclovir Consumer Information
- Breastfeeding Support Group
- Safe Medications during Breastfeeding
- Medicine use while Breastfeeding
- Medicine use during Pregnancy
Disclaimer: This information is not intended as a substitute for professional judgment. You should consult your healthcare provider for breastfeeding advice related to your particular situation. Use of this website signifies your agreement to the Terms of Use and Online Privacy Policy.
